xen/pciback: miscellaneous adjustments

This is a minor bugfix and a set of small cleanups; as it is not clear
whether this needs splitting into pieces (and if so, at what
granularity), it is a single combined patch.
- add a missing return statement to an error path in
  kill_domain_by_device()
- use pci_is_enabled() rather than raw atomic_read()
- remove a bogus attempt to zero-terminate an already zero-terminated
  string
- #define DRV_NAME once uniformly in the shared local header
- make DRIVER_ATTR() variables static
- eliminate a pointless use of list_for_each_entry_safe()
- add MODULE_ALIAS()
- a little bit of constification
- adjust a few messages
- remove stray semicolons from inline function definitions

Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v1: Dropped the resource_size fix, altered the description]
[v2: Fixed cleanpatch.pl comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/xen-pciback/conf_space.c

@@ -15,7 +15,6 @@
 #include "conf_space.h"
 #include "conf_space_quirks.h"
 
-#define DRV_NAME	"xen-pciback"
 static int permissive;
 module_param(permissive, bool, 0644);
 

drivers/xen/xen-pciback/conf_space_header.c

@@ -15,7 +15,6 @@ struct pci_bar_info {
 	int which;
 };
 
-#define DRV_NAME	"xen-pciback"
 #define is_enable_cmd(value) ((value)&(PCI_COMMAND_MEMORY|PCI_COMMAND_IO))
 #define is_master_cmd(value) ((value)&PCI_COMMAND_MASTER)
 
@@ -25,7 +24,7 @@ static int command_read(struct pci_dev *dev, int offset, u16 *value, void *data)
 	int ret;
 
 	ret = xen_pcibk_read_config_word(dev, offset, value, data);
-	if (!atomic_read(&dev->enable_cnt))
+	if (!pci_is_enabled(dev))
 		return ret;
 
 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {

drivers/xen/xen-pciback/conf_space_quirks.c

@@ -12,7 +12,6 @@
 #include "conf_space_quirks.h"
 
 LIST_HEAD(xen_pcibk_quirks);
-#define	DRV_NAME	"xen-pciback"
 static inline const struct pci_device_id *
 match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
 {
@@ -36,7 +35,7 @@ static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev)
 			goto out;
 	tmp_quirk = NULL;
 	printk(KERN_DEBUG DRV_NAME
-	       ":quirk didn't match any device xen_pciback knows about\n");
+	       ": quirk didn't match any device known\n");
 out:
 	return tmp_quirk;
 }

drivers/xen/xen-pciback/passthrough.c

@@ -176,7 +176,7 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
 	return 1;
 }
 
-struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
+const struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
 	.name           = "passthrough",
 	.init           = __xen_pcibk_init_devices,
 	.free		= __xen_pcibk_release_devices,

drivers/xen/xen-pciback/pci_stub.c

@@ -21,8 +21,6 @@
 #include "conf_space.h"
 #include "conf_space_quirks.h"
 
-#define DRV_NAME	"xen-pciback"
-
 static char *pci_devs_to_hide;
 wait_queue_head_t xen_pcibk_aer_wait_queue;
 /*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops,
@@ -514,12 +512,14 @@ static void kill_domain_by_device(struct pcistub_device *psdev)
 	int err;
 	char nodename[PCI_NODENAME_MAX];
 
-	if (!psdev)
+	if (!psdev) {
 		dev_err(&psdev->dev->dev,
 			"device is NULL when do AER recovery/kill_domain\n");
+		return;
+	}
+
 	snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0",
 		psdev->pdev->xdev->otherend_id);
-	nodename[strlen(nodename)] = '\0';
 
 again:
 	err = xenbus_transaction_start(&xbt);
@@ -605,7 +605,7 @@ static pci_ers_result_t common_process(struct pcistub_device *psdev,
 	if (test_bit(_XEN_PCIF_active,
 		(unsigned long *)&psdev->pdev->sh_info->flags)) {
 		dev_dbg(&psdev->dev->dev,
-			"schedule pci_conf service in xen_pcibk\n");
+			"schedule pci_conf service in " DRV_NAME "\n");
 		xen_pcibk_test_and_schedule_op(psdev->pdev);
 	}
 
@@ -995,8 +995,7 @@ static ssize_t pcistub_slot_add(struct device_driver *drv, const char *buf,
 		err = count;
 	return err;
 }
-
-DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
+static DRIVER_ATTR(new_slot, S_IWUSR, NULL, pcistub_slot_add);
 
 static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
 				   size_t count)
@@ -1015,8 +1014,7 @@ static ssize_t pcistub_slot_remove(struct device_driver *drv, const char *buf,
 		err = count;
 	return err;
 }
-
-DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
+static DRIVER_ATTR(remove_slot, S_IWUSR, NULL, pcistub_slot_remove);
 
 static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
 {
@@ -1039,8 +1037,7 @@ static ssize_t pcistub_slot_show(struct device_driver *drv, char *buf)
 
 	return count;
 }
-
-DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
+static DRIVER_ATTR(slots, S_IRUSR, pcistub_slot_show, NULL);
 
 static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
 {
@@ -1069,8 +1066,7 @@ static ssize_t pcistub_irq_handler_show(struct device_driver *drv, char *buf)
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 	return count;
 }
-
-DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
+static DRIVER_ATTR(irq_handlers, S_IRUSR, pcistub_irq_handler_show, NULL);
 
 static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
 					  const char *buf,
@@ -1106,7 +1102,8 @@ static ssize_t pcistub_irq_handler_switch(struct device_driver *drv,
 		err = count;
 	return err;
 }
-DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL, pcistub_irq_handler_switch);
+static DRIVER_ATTR(irq_handler_state, S_IWUSR, NULL,
+		   pcistub_irq_handler_switch);
 
 static ssize_t pcistub_quirk_add(struct device_driver *drv, const char *buf,
 				 size_t count)
@@ -1170,8 +1167,8 @@ static ssize_t pcistub_quirk_show(struct device_driver *drv, char *buf)
 
 	return count;
 }
-
-DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show, pcistub_quirk_add);
+static DRIVER_ATTR(quirks, S_IRUSR | S_IWUSR, pcistub_quirk_show,
+		   pcistub_quirk_add);
 
 static ssize_t permissive_add(struct device_driver *drv, const char *buf,
 			      size_t count)
@@ -1236,8 +1233,8 @@ static ssize_t permissive_show(struct device_driver *drv, char *buf)
 	spin_unlock_irqrestore(&pcistub_devices_lock, flags);
 	return count;
 }
-
-DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show, permissive_add);
+static DRIVER_ATTR(permissive, S_IRUSR | S_IWUSR, permissive_show,
+		   permissive_add);
 
 static void pcistub_exit(void)
 {
@@ -1374,3 +1371,4 @@ module_init(xen_pcibk_init);
 module_exit(xen_pcibk_cleanup);
 
 MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:pci");

drivers/xen/xen-pciback/pciback.h

@@ -15,6 +15,8 @@
 #include <linux/atomic.h>
 #include <xen/interface/io/pciif.h>
 
+#define DRV_NAME	"xen-pciback"
+
 struct pci_dev_entry {
 	struct list_head list;
 	struct pci_dev *dev;
@@ -89,7 +91,7 @@ typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
  *  passthrough - BDFs are exactly like in the host.
  */
 struct xen_pcibk_backend {
-	char *name;
+	const char *name;
 	int (*init)(struct xen_pcibk_device *pdev);
 	void (*free)(struct xen_pcibk_device *pdev);
 	int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev,
@@ -104,9 +106,9 @@ struct xen_pcibk_backend {
 			       unsigned int devfn);
 };
 
-extern struct xen_pcibk_backend xen_pcibk_vpci_backend;
-extern struct xen_pcibk_backend xen_pcibk_passthrough_backend;
-extern struct xen_pcibk_backend *xen_pcibk_backend;
+extern const struct xen_pcibk_backend xen_pcibk_vpci_backend;
+extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend;
+extern const struct xen_pcibk_backend *xen_pcibk_backend;
 
 static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 					struct pci_dev *dev,
@@ -116,13 +118,14 @@ static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
 	if (xen_pcibk_backend && xen_pcibk_backend->add)
 		return xen_pcibk_backend->add(pdev, dev, devid, publish_cb);
 	return -1;
-};
+}
+
 static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
 					     struct pci_dev *dev)
 {
 	if (xen_pcibk_backend && xen_pcibk_backend->free)
 		return xen_pcibk_backend->release(pdev, dev);
-};
+}
 
 static inline struct pci_dev *
 xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
@@ -131,7 +134,8 @@ xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
 	if (xen_pcibk_backend && xen_pcibk_backend->get)
 		return xen_pcibk_backend->get(pdev, domain, bus, devfn);
 	return NULL;
-};
+}
+
 /**
 * Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
 * before sending aer request to pcifront, so that guest could identify
@@ -148,25 +152,29 @@ static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
 		return xen_pcibk_backend->find(pcidev, pdev, domain, bus,
 					       devfn);
 	return -1;
-};
+}
+
 static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
 {
 	if (xen_pcibk_backend && xen_pcibk_backend->init)
 		return xen_pcibk_backend->init(pdev);
 	return -1;
-};
+}
+
 static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
 					      publish_pci_root_cb cb)
 {
 	if (xen_pcibk_backend && xen_pcibk_backend->publish)
 		return xen_pcibk_backend->publish(pdev, cb);
 	return -1;
-};
+}
+
 static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
 {
 	if (xen_pcibk_backend && xen_pcibk_backend->free)
 		return xen_pcibk_backend->free(pdev);
-};
+}
+
 /* Handles events from front-end */
 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
 void xen_pcibk_do_op(struct work_struct *data);

drivers/xen/xen-pciback/pciback_ops.c

@@ -10,7 +10,6 @@
 #include <linux/sched.h>
 #include "pciback.h"
 
-#define DRV_NAME	"xen-pciback"
 int verbose_request;
 module_param(verbose_request, int, 0644);
 

drivers/xen/xen-pciback/vpci.c

@@ -12,7 +12,6 @@
 #include "pciback.h"
 
 #define PCI_SLOT_MAX 32
-#define DRV_NAME	"xen-pciback"
 
 struct vpci_dev_data {
 	/* Access to dev_list must be protected by lock */
@@ -150,9 +149,9 @@ static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
 	spin_lock_irqsave(&vpci_dev->lock, flags);
 
 	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
-		struct pci_dev_entry *e, *tmp;
-		list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
-					 list) {
+		struct pci_dev_entry *e;
+
+		list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
 			if (e->dev == dev) {
 				list_del(&e->list);
 				found_dev = e->dev;
@@ -247,7 +246,7 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
 	return found;
 }
 
-struct xen_pcibk_backend xen_pcibk_vpci_backend = {
+const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
 	.name		= "vpci",
 	.init		= __xen_pcibk_init_devices,
 	.free		= __xen_pcibk_release_devices,

drivers/xen/xen-pciback/xenbus.c

@@ -13,7 +13,6 @@
 #include <asm/xen/pci.h>
 #include "pciback.h"
 
-#define	DRV_NAME	"xen-pciback"
 #define INVALID_EVTCHN_IRQ  (-1)
 struct workqueue_struct *xen_pcibk_wq;
 
@@ -176,7 +175,7 @@ static int xen_pcibk_attach(struct xen_pcibk_device *pdev)
 	if (magic == NULL || strcmp(magic, XEN_PCI_MAGIC) != 0) {
 		xenbus_dev_fatal(pdev->xdev, -EFAULT,
 				 "version mismatch (%s/%s) with pcifront - "
-				 "halting xen_pcibk",
+				 "halting " DRV_NAME,
 				 magic, XEN_PCI_MAGIC);
 		goto out;
 	}
@@ -724,7 +723,7 @@ static struct xenbus_driver xenbus_xen_pcibk_driver = {
 	.otherend_changed	= xen_pcibk_frontend_changed,
 };
 
-struct xen_pcibk_backend *xen_pcibk_backend;
+const struct xen_pcibk_backend *__read_mostly xen_pcibk_backend;
 
 int __init xen_pcibk_xenbus_register(void)
 {